1. Field of the Invention
The present invention relates in general to a sheet storage device and a sheet processing apparatus using such device, and more particularly to a sheet storage device using a toothed portion and a resilient member pushing against each other to provide a resisting force to two guide plates, and a sheet processing apparatus using such device.
2. Related Art
Automatic document feeders are widely used in scanners, printers and multi-function peripherals. The sheets to be placed on the automatic document feeder are usually decided by the user. Thus, the automatic document feeder is usually equipped with a left guide plate and a right guide plate for clamping and guiding the sheet or sheets, so that the user can manually perform the adjustment according to the width of the sheet to avoid the skew upon transportation of the sheet.
The sheet width adjusting mechanism on a conventional automatic document feeder is usually achieved by a pinion and two racks, which are disposed on two sides of the pinion and mesh with the pinion. When the user moves the left guide plate, the pinion is rotated by the left guide plate and thus moves the right guide plate. As a result, the left guide plate and the right guide plate may be moved synchronously.
Although the user can smoothly and continuously adjust the distance between the two guide plates of the sheet width adjusting mechanism, the user tends to adjust the gap between the two guide plates to be too small when no resisting force is present, so that the two edges of the sheet are pressed. This condition further tends to occur when only one sheet, a few sheets or the very thin sheets are processed, and the user must carefully adjust the distance between the two guide plates back and forth in an inconvenient manner.